Wavelet analysis of pressure fluctuation signals in a gas-solid fluidized bed

It has been shown that much dynamic information is hidden in the pressure fluctuation signals of a gas-solid fluidized bed. Unfortunately, due to the random and capricious nature of this signal, it is hard to realize reliable analysis using traditional signal processing methods such as statistical analysis or spectral analysis, which is done in Fourier domain. Information in different frequency band can be extracted by using wavelet analysis. On the evidence of the composition of the pressure fluctuation signals, energy of low frequency (ELF) is proposed to show the transition of fluidized regimes from bubbling fluidization to turbulent fluidization. Plots are presented to describe the fluidized bed‘s evolution to help identify the state of different flow regimes and provide a characteristic curve to identify the fluidized status effectively and reliably.     

多层盘式废轮胎裂解塔中试油品的提纯实验研究

多层盘式废轮胎裂解塔中试油品富含多种有用化学物质，但闪点仅有19．2℃，为确保其贮存安全性和提升经济附加值，进行了热解油品的间歇常压分馏试验，并采用气相色谱-质谱分析（GC／MS）和化学分析相结合的方法，掌握了多层盘式废轮胎裂解塔中试油品的组分及相应含量，这对确定有用组分的分馏切割温度具有重要参考价值．同时通过热解油中甲苯、二甲苯的分馏提纯试验，确定它们在85-110℃和123-145℃两温度区间能分别实现有效富集，其中甲苯含量可从热解油中的7．65％富集到68．52％，二甲苯含量能从热解油中的10．09％富集达到65．20％．另分离出以甲苯、二甲苯为主的轻质组分后，废轮胎热解油的闭口闪点升高到97．2℃，贮存使用更为安全．